Method for coding and decoding an information symbol
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| Title: | Method for coding and decoding an information symbol |
|---|---|
| Patent Number: | 7,333,552 |
| Publication Date: | February 19, 2008 |
| Appl. No: | 10/363968 |
| Application Filed: | September 04, 2001 |
| Abstract: | A method and a device for the coding and/or decoding of an information symbol for transmission over a transmission channel or a received signal value is described and illustrated, whereby a channel symbol used for coding is selected from at least two available channel symbols by means of a pre-calculated expected received signal value. The pre-calculation is achieved, based on the echo properties of the transmission channel and transmission values already sent. A pre-coding method with low receiver-side calculation requirement is thus prepared, whereby the information symbol can be transmitted by means of various channel symbols and thus various transmission values can also be transmitted. The possible selections may be used for minimization of the transmission energy and/or to achieve a minimal disturbance or even a constructive effect through the inter-symbol interference occurring on transmission. |
| Inventors: | Koslar, Manfred (Berlin, DE); Hach, Rainer (Berlin, DE) |
| Assignees: | Nanotron Technologies GmbH (Berlin, DE) |
| Claim: | 1. A method for encoding of an information symbol associated with an information symbol alphabet to be transmitted across a transmission channel, comprising: a) selecting a channel symbol alphabet having at least one more element than the information symbol alphabet; b) determining a postoscillation behavior of the transmission channel; c) calculating in advance reception signal values anticipated at a receive end of the transmission channel when transmitting selectable channel symbols, based on the postoscillation behavior; d) selecting one of the selectable channel symbols in relation to the reception signal values; e) using the selected channel symbol for encoding of the information symbol; f) calculating a sending signal value as a function of the selected channel symbol and the reception signal; and g) outputting the sending signal value. |
| Claim: | 2. The method of claim 1 , wherein at least two channel symbols are provided for each information symbol. |
| Claim: | 3. The method of claim 1 , wherein the reception signal values define an uncertainty region; and wherein the selection of the selectable channel symbol is done based on its position relative to the uncertainty region. |
| Claim: | 4. The method of claim 3 , wherein the uncertainty region is determined in relation to the preoscillation behavior of the transmission channel. |
| Claim: | 5. The method of claim 1 , wherein preoscillation and postoscillation behavior of the transmission channel is determined by means of the channel pulse response. |
| Claim: | 6. The method of claim 5 , wherein compensating for a deviation between measured and real channel pulse response at the receiver side using an adaptive equalizer. |
| Claim: | 7. The method of claim 3 , wherein the selection of the selectable channel symbol is done in relation to a smallest correction value relative to one or more corner points of the uncertainty region. |
| Claim: | 8. The method of claim 3 , wherein the selection or the selectable channel symbol is done in relation to a smallest correction value relative to a most distant point of the uncertainty region. |
| Claim: | 9. The method of claim 1 , wherein a sending value “0” is used to transmit a channel symbol where an anticipated reception signal value caused by inter-symbol interference is situated within a region associated with a higher probability of detection for the channel symbol being transmitted at the receiver side. |
| Claim: | 10. The method of claim 1 , wherein a difference between a selected channel symbol and anticipated worse case inter-symbol interference is used as a sending value to transmit a channel symbol being sent where the corresponding reception signal value is located in a region defined and subtended by channel symbols. |
| Claim: | 11. The method of claim 9 , wherein limiting of the region is carried out in that complex components associated with the sending signal value are limited to a maximum value. |
| Claim: | 12. The method of claim 11 , wherein the limiting of the region is done in that an amplitude of the complex components associated with the sending signal value is limited to a maximum value. |
| Claim: | 13. The method of claim 1 , wherein the information symbol being transmitted is a BPSK symbol and the selectable channel symbols are QPSK symbols. |
| Claim: | 14. The method of claim 1 , wherein the set of possible sending signal values is not countable. |
| Claim: | 15. The method of claim 1 , wherein the set of possible sending signal values is countable and thus discrete. |
| Claim: | 16. The method of claim 15 , wherein a pre-encoder function is implemented in the form of a table of values after determining transmission channel properties. |
| Claim: | 17. The method of claim 16 , wherein the pre-encoding function is realized in the form of a table of values for probable types of channel pulse response defined prior to the determination of the transmission channel properties. |
| Claim: | 18. The method of claim 1 , wherein the sending signal value is determined in relation to possible channel symbol sequences which can be used for subsequent information symbols being transmitted. |
| Claim: | 19. The method of claim 1 , wherein the selection of channel symbols is random in order to accomplish a scrambling function. |
| Claim: | 20. The method of claim 1 , wherein at least one of a higher-stage PSK modulation or a DPSK modulation is used for the encoding of the information symbol. |
| Claim: | 21. A method for decoding a reception signal value received via a transmission channel, comprising: a) determining a QPSK channel symbol from the reception signal value using a decision-making function, said determination being made in relation to a quadrant in which the reception signal is located; b) assigning an information symbol, for which the determined channel symbol is selectable during the encoding; c) determining (i) a detection uncertainty in relation to a distance between the reception signal value and (ii) limits for a secure decision region associated with the channel symbol, wherein the distance is at least one of a Euclidean distance and a Hamming distance; and d) outputting data which is representative of one or more information symbols using the detection uncertainty and/or the limits for the secure decision region. |
| Claim: | 22. The method of claim 1 , wherein a set of information symbols to be transmitted in future is used in selecting the current channel symbol. |
| Claim: | 23. The method of claim 22 wherein a mean and maximum sending value energy is minimized by taking into account future information symbols to be transmitted when selecting the current channel symbol. |
| Claim: | 24. A device for encoding an information signal to be transmitted across a transmission channel, comprising: a) an encoder to furnishing a plurality of selectable channel symbols for the information symbol being transmitted; b) a computing unit to compute one or more reception signal values anticipated at a reception end of the transmission channel in relation to transmission of the plurality of selectable channel symbols, and in relation to postoscillation behavior of the transmission channel; c) a selection unit to selecting one of the plurality of selectable channel symbols in accordance with the anticipated reception signal values and encoding the information symbol being transmitted using the selected channel symbol; and d) a sending value computing unit to: (i) compute a sending value as a function of the selected channel symbol and the anticipated reception values and (ii) output the sending value. |
| Claim: | 25. The device of claim 24 , wherein the computing unit further comprises: a first storage unit to store sending values previously sent; a second storage unit to store channel coefficients describing the postoscillation behavior of the transmission channel; a multiplication unit to multiply the sending values previously sent with the corresponding channel coefficients; and an addition unit to add results from the multiplication unit. |
| Claim: | 26. The device of claim 25 , wherein the anticipated reception signal values are calculated in the computing unit in relation to an addition result received from the addition unit, the selected channel symbol, and an anticipation value which takes into account the preoscillation behavior of the transmission channel. |
| Claim: | 27. The device of claim 26 , further including a prefilter adapted to the transmission channel to diminish the preoscillation behavior of the transmission channel. |
| Claim: | 28. A device for decoding a reception signal value received via a transmission channel, comprising: a decision-making unit comprising a detector to determine a channel symbol from the reception signal value using a decision-making function that considers a quadrant in which the reception signal is located; an assignment unit to assign an information symbol for which the determined channel symbol is selectable during encoding; and an error assessment unit to: (i) determine a detection uncertainty based on a distance between the reception signal value and limits of a decision-making region considered to be secure for the determined channel symbol and (ii) output data which is representative of one or more information symbols using the detection uncertainty and/or the limits for the decision-making region. |
| Current U.S. Class: | 375/285 |
| Patent References Cited: | 5159610 October 1992 Eyuboglu et al. 5455839 October 1995 Eyuboglu 5570388 October 1996 Halpern 5696769 December 1997 Choi et al. 44 40 947 April 1996 199 12 825 August 2000 0 555 013 August 1993 |
| Primary Examiner: | Kumar, Pankaj |
| Attorney, Agent or Firm: | Steinberg, Neil A. |
| Accession Number: | edspgr.07333552 |
| Database: | USPTO Patent Grants |
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